Denver pot holiday bringing crowds, tight security

FILE - This April 20, 2012 file photo shows a cloud of smoke covering the crowd at the Denver 420 rally in Civic Center Park. Denver Police are bracing for this year's event on Saturday, April 20, 2013 which is expected to draw a record crowd of 80,000 people. (AP Photo/The Denver Post, Daniel Petty, File)

As tens of thousands of people gather to celebrate and smoke marijuana in Denver, the police will be out in full force.

But it’s not the pot smoking they’re concerned about at the yearly event, billed as the nation’s largest April 20 celebration. Instead, the police say they’re focused on crowd security in light of attacks that killed three at the finish line of the Boston Marathon.

“We’re aware of the events in Boston,” said Denver police spokesman Aaron Kafer, who declined to give specifics about security measures being taken. “Our message to the public is that if you see something, say something.”

Organizers say the event – which drew 50,000 people last year – could bring a record 80,000 this year, since it’s the first celebration since Colorado and Washington voted to make pot legal for recreational use.

Even with the legalization, Colorado law bans open and public marijuana use. Still, authorities generally look the other way. The smoke hangs thick over a park at the base of the state capitol, and live music keeps the crowd entertained well past the moment of group smoking at 4:20 p.m.